Uranium Recovery from Sulfate-Based Acidic Soil Washing Effluent Using Ion-Exchange Resins

摘要

This study aimed to recover U(Ⅵ) from sulfate-based acidic soil-washing effluent using the ion-exchange method. For effective ion exchange of U(Ⅵ) under acidic conditions, one chelate resin (Purolite S950) stable under low pH conditions and two anion-exchange resins (Ambersep 400 SO4 and 920U SO4) used in sulfuric acid leaching systems were selected. The ionic form of U(Ⅵ) changed according to the initial pH conditions of the soil-washing effluent, which affected the U(Ⅵ)-ion removal efficiency by the ion-exchange resins. U(Ⅵ) ion exchange was consistent with the Langmuir model and followed pseudo-second-order kinetics. Thermodynamic experiments revealed that the U(Ⅵ) ion exchange by the ion-exchange resins is an endo-thermic and spontaneous process. U(Ⅵ) was effectively desorbed from the ion-exchange resins using 0.5 M H_2SO_4 or Na_2CO_3 solution.